CVE-2021-30983 in iOS
Summary
by MITRE • 08/25/2021
A buffer overflow issue was addressed with improved memory handling. This issue is fixed in iOS 15.2 and iPadOS 15.2. An application may be able to execute arbitrary code with kernel privileges.
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Analysis
by VulDB Data Team • 03/08/2026
The vulnerability identified as CVE-2021-30983 represents a critical buffer overflow flaw that existed within the iOS and iPadOS operating systems prior to version 15.2. This issue stems from inadequate memory management practices that allowed malicious applications to exploit memory boundaries and potentially execute arbitrary code with elevated kernel privileges. The vulnerability specifically affects the kernel-level memory handling mechanisms that govern how system resources are allocated and managed during application execution. Security researchers identified that the flaw occurred when the system processed certain memory operations that exceeded allocated buffer limits, creating opportunities for attackers to manipulate system behavior through crafted inputs. The root cause of this vulnerability aligns with common software security weaknesses classified under CWE-121, which deals with stack-based buffer overflows, and CWE-122, which addresses heap-based buffer overflows. These classifications highlight the fundamental nature of the flaw as a memory safety issue that can be exploited to gain unauthorized system access.
The operational impact of CVE-2021-30983 extends far beyond typical application-level security breaches, as successful exploitation can result in complete system compromise with kernel-level privileges. This means that an attacker who successfully exploits this vulnerability could gain unrestricted access to all system resources, including the ability to read and modify any file on the device, install malicious applications without user consent, and potentially access sensitive data stored in protected system areas. The attack vector typically involves an application that can be installed on the device through legitimate app stores or through other means, making this vulnerability particularly dangerous as it can be exploited through seemingly normal application usage. The implications for enterprise environments are severe, as this vulnerability could allow attackers to compromise employee devices and potentially gain access to corporate networks, sensitive business data, and internal systems that rely on these devices for connectivity.
The exploitation of this vulnerability demonstrates characteristics consistent with techniques found in the MITRE ATT&CK framework under the T1059 category, which covers command and control using application layer protocols, and T1068, which addresses exploit for privilege escalation. Attackers leveraging this flaw would typically need to craft specific payloads that trigger the buffer overflow condition, potentially using techniques such as return-oriented programming or other advanced exploitation methods to achieve code execution. The fix implemented by Apple in iOS 15.2 and iPadOS 15.2 addresses the issue through enhanced memory management controls that prevent buffer overflows from occurring during system operations. This patch demonstrates Apple's approach to mitigating memory safety issues through improved bounds checking and memory allocation mechanisms. Organizations should prioritize updating affected systems to version 15.2 or later, as this update not only resolves the immediate vulnerability but also strengthens overall system security posture against similar memory-based attacks that could potentially target other components of the operating system. The vulnerability serves as a reminder of the critical importance of maintaining current system updates and implementing comprehensive security monitoring to detect potential exploitation attempts.